public class RubberDuck extends Duck {
    public RubberDuck(String color, double heavy) {
        super(color, heavy);
    }

    public void setHeavy(double heavy, String unit) {
        this.heavy = heavy;
        System.out.println("重量单位：" + unit);
    }

    @Override
    public void fly() {
        System.out.println("橡胶鸭不会真的飞行");
    }

    @Override
    public void quack() {
        System.out.println("橡胶鸭发出 squeak 声");
    }
}